Solvent Effect Correlations for Acetone: IR versus NMR Data for the Carbonyl Group

A linear relationship is found to exist between the carbonyl stretching frequency ( vC=O) and the carbon-13 chemical shift data [δ( 13 C=O)] for the carbonyl group of 0.345 mole % acetone in a mixed solvent solution ranging from 1.5 to 70.8 mole % CHCl 3 /CCl 4 . The correlation shows that as vC=O decreases in frequency δ( 13 C=O) increases in frequency as the concentration of CHCl 3 increases in the acetone/CHCl 3 /CCl 4 solutions. However, the relationship between vC=O and the mole % CHCl 3 /CCl 4 and between δ( 13 C=O) and the mole % CHCl 3 /CCl 4 is not linear over the concentration range studied. Both hydrogen bonding and bulk dielectric effects most likely contribute to the change in both the IR and NMR data with change in the CHCl 3 /CCl 4 ratio.